Browsing by Author "Tsai, Yen-Pin"

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Design of optical components for a light emitting diode zoom illumination system
(2011-03-01)
Tsai, Yen-Pin
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Hung, Chinghua
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機械工程學系
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Department of Mechanical Engineering
In this article, we report an optical design for a light emitting diode that can achieve high illumination quality using two hyperbolic reflectors. The relative movements of the reflectors and the light source produce a zoom function that can change the illumination beam from convergence to divergence. This study uses optical software ZEMAX for system simulation, and optimization was performed to select reflector parameters with the objectives of both improving floodlight uniformity and spotlight efficiency. Finally, experiments were conducted to verify the validity of the design, and the results corresponded well to the zoom illumination simulations.
Development of a new apparatus for ultrasonic vibration-assisted glass hot embossing process
(2013-01-01)
Hung, Jung-Chung
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Tsai, Yen-Pin
;
Hung, Chinghua
;
機械工程學系
;
Department of Mechanical Engineering
A new apparatus for an ultrasonic vibration-assisted glass hot embossing process has been developed. The upper die constitutes the ultrasonic vibrating device, and a cooler is provided to protect the transducer from the high operating temperatures. An ultrasonic horn originally designed for use at room temperature was modified to ensure correct operation of ultrasonic vibrating device for high temperature use. Because the load cell is located inside a vacuum chamber, the detection of the force applied to the glass during the forming process is not significantly impacted by external forces, and thus, a precise force history of the forming glass can be obtained. Flat hot embossing experiments were performed to investigate the effect of ultrasonic vibration on the amount of force required during forming, and Fresnel structure hot embossing experiments were then conducted to investigate the improvement in molding accuracy gained through ultrasonic vibration. The experimental results are taken to validate the manufacturing potential of the developed apparatus and the improvement in formability achieved by applying ultrasonic vibration. (c) 2012 Elsevier Inc. All rights reserved.
Finite Element Analysis of an Ultrasonic Vibration Device at High Temperatures
(2016-06)
Lan Phuong Nguyen
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Tsai, Yen-Pin
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Hung, Jung-Chung
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Hsieh, Yi-Chun
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Hung, Chinghua
Ultrasonic-vibration-assisted forming has been extensively adopted in plastic manufacturing processes. Ultrasonic vibration contributes to enhancing material formability and product quality and to reducing manufacturing costs by improving frictional conditions and increasing the temperature of materials. However, designing a suitable ultrasonic vibration system for processes conducted at high working temperatures, such as the ultrasonic vibration-assisted glass hot embossing process, is difficult because of complex thermal boundaries and material properties. In this study, an ultrasonic vibration system that can be used at high working temperatures was analyzed using the finite element method and ANSYS commercial software. The simulation results obtained from thermal, modal, and harmonic response analyses were compared with experimental measurements to confirm the validity of the numerical analysis. The resulting finite element module can be used in designing the components of ultrasonic vibration devices that can be used at high working temperatures.
Optimization of Ultrasonic Plastic Welding Horns on Amplitude Uniformity
(2012)
Hung, Jung-Chung
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Tsai, Yen-Pin
;
Hung, Chinghua
;
機械工程學系
;
Department of Mechanical Engineering
This research integrated finite element analysis (FEA) and optimum design to obtain a fast, accurate and automatic optimization system for the design of an ultrasonic horn. The optimization system was developed to achieve uniform amplitude distribution on the output surface of a block shaped horn for the ultrasonic plastic welding. Agreement between the experimental and numerical data proved that this optimization system was efficient in the design of ultrasonic horns.
Ultrasonic vibration-assisted optical glass hot embossing process
(2012-06-01)
Tsai, Yen-Pin
;
Hung, Jung-Chung
;
Yin, Li-Chao
;
Hung, Chinghua
;
機械工程學系
A homemade apparatus was used to apply ultrasonic-vibration to assist the glass hot embossing processes. To operate at high temperatures for glass hot embossing, the ultrasonic vibration system was appropriately designed with an embedded cooling system, and an ultrasonic horn was specifically modified for high-temperature use. Molds with both V-groove and Fresnel structures were manufactured for hot embossing experiments on PSK-100 glass. The heights of the molded structures were increased significantly with the assistance of ultrasonic vibration. This technology demonstrates the capability to upgrade the performance of the glass hot embossing process.